REPORT OF COMMITTEE ON OBSERVATORIES I45 



[From Professor Henry Creto, Director of the Physical Laboratory of 

 Northwestern University , Evatiston, Illinois.'] 



February io, 1903. 



I have not earlier replied to your circular letter of the 30th ultimo 

 for the reason that I have nothing of value to contribute in the way 

 of suggestions. Congratulations are certainly due to the astrophys- 

 ical world on the splendid prospects set before it by the Carnegie 

 Institution. 



My own experience, my reason, and my reading all lead me to 

 think that you are not likely to put too much emphasis upon the 

 necessity of untying the bundle of sticks before you attempt to 

 break them. By which I mean to say that you are hardly likely to 

 find at any one station the best conditions for undertaking more 

 than one of the three problems which you outline. 



The best conditions for the solution of any of these questions 

 would seem to me something like the following : 



1 . A carefully and intelligently selected site to which an investi- 

 gator might go with confidence. 



2. A single, definite, and not too general problem; at least, a 

 single problem at a time. 



3. The selection of two men whose interest and ability in the 

 matter no one doubts. 



4. A simple, plain, but adequate material equipment in all except 

 the central and essential instrument, and then make this the most 

 powerful and most ejGBcient in existence. 



5. Study the men j^ou put in charge, see that they are comfort- 

 able, but not "too comfortable," and, above all else, see that the 

 conditions (mechanician, etc.) are such that these men's time can 

 all go to the problem in hand. In other words, leave your men 

 "foot free," and then hold them responsible either for results or 

 for difficulties which are certainly insurmountable. 



6. Energy without haste ; test men and sites deliberately. 



Of all the problems which you mention, the most pressing appears 

 to me to be the need of a continuous record of what is going on at 

 the solar surface. Psychologists often find abnormal cases the most 

 instructive. It may be so with solar studies. Next most important 

 appears to me the horizontal telescope of large aperture. I think 

 this deserves a fair trial in the best attainable spot on the globe, both 

 for spectroscopic and for photographic work. 



